feat: ui polish (sticky header, dark mode, flat inputs)

src/App.tsx

@@ -54,11 +54,16 @@ function App() {
   }
 
   return (
-    <main className="container">
-      <h1>AI Code Assistant</h1>
-
+    <main
+      className="container"
+      style={{ height: "100vh", padding: 0, maxWidth: "100%" }}
+    >
       {!projectPath ? (
-        <div className="selection-screen">
+        <div
+          className="selection-screen"
+          style={{ padding: "2rem", maxWidth: "800px", margin: "0 auto" }}
+        >
+          <h1>AI Code Assistant</h1>
           <p>
             Please select a project folder to start the Story-Driven Spec
             Workflow.
@@ -66,31 +71,8 @@ function App() {
           <button onClick={selectProject}>Open Project Directory</button>
         </div>
       ) : (
-        <div className="workspace">
-          <div
-            className="toolbar"
-            style={{
-              padding: "10px",
-              background: "#f0f0f0",
-              borderRadius: "4px",
-              color: "#333",
-              display: "flex",
-              justifyContent: "space-between",
-              alignItems: "center",
-            }}
-          >
-            <span>
-              <strong>Active Project:</strong> {projectPath}
-            </span>
-            <button
-              onClick={closeProject}
-              style={{ padding: "5px 10px", fontSize: "0.9em" }}
-            >
-              Close
-            </button>
-          </div>
-          <hr style={{ margin: "20px 0" }} />
-          <Chat />
+        <div className="workspace" style={{ height: "100%" }}>
+          <Chat projectPath={projectPath} onCloseProject={closeProject} />
         </div>
       )}